Correction tape dispensers can be used to cover mistakes made on a substrate, such as a sheet of paper, including writing or typing errors. In a common example, a correction tape dispenser includes a housing inside which a supply reel and a take-up reel are disposed. A carrier ribbon has a first end wound about the supply reel and a second end wound about a take-up reel. One side of the carrier ribbon is coated with a corrective coating that is used to cover a mistake on a substrate. Some known correction tape dispensers exist, which have supply and take-up reels that rotate about a common axis with the supply reel being coupled to drive the take-up reel through a clutch mechanism.
An applicator tip having a platform with a front edge is attached to the housing with the front edge being outside the housing. The applicator tip assists in the transfer of the corrective coating from the carrier ribbon to the paper.
The housing can be held in a consumer's hand during use. In passing from the supply reel to the take-up reel, the carrier ribbon is directed to the applicator tip, across the platform, around the front edge, and back to the take-up reel. The front edge of the applicator tip creates a sharp bend in the ribbon to assist in releasing the corrective coating from the ribbon. The front edge presses the carrier ribbon against the surface of a sheet of paper or other substrate in order to transfer the corrective coating from the carrier ribbon onto the paper so as to cover a mistake made thereon and to facilitate the correction of the mistake.
As the front edge is moved across the paper, carrier ribbon with a fresh corrective coating is drawn from the supply reel while the take-up reel is driven to wind up the carrier ribbon which has passed over the front edge and hence from which the corrective coating has been removed. Thus, a straight continuous strip of corrective coating is laid down on the paper surface until the forward movement of the applicator tip is stopped and the tip is lifted away from the paper.
With such correction tape dispensers, it is well known that the pulling force required to apply the correction tape to the substrate grows steadily throughout the life of the product while the torque required to draw the correction tape off of the supply reel remains substantially constant. The torque equals the pulling force multiplied by the radius of the correction tape stored on the supply reel. It is intuitive that the radius of the supply reel decreases as the supply of correction tape decreases. Therefore, to maintain a constant torque, the pulling force applied to the correction tape must be increased to offset the decrease in the radius of tape.